Scientists are supposed to be objective, but they are not immune to the charms of the denizens of Deep Sea World. Marine biologist Chris Smith, one of the team of aquarists who care for the wildlife at the attraction in North Queensferry, Fife, admits they do get attached to the animals.

“Some of the characters, like these puffer fish, are very hard to resist,” he says, indicating lively orange bundles darting around a blue tank. “They have cute faces and big dark eyes that follow you around the aquarium. You try to be objective but you can’t help falling for them.”

In this respect Mr Smith is no different from the 25,000 schoolchildren who visit Deep Sea World each year. They too have their favourites.

“I like the sharks because they do tricks with the divers,” says Kai Mackie, a P3 pupil from Nether Currie Primary in Edinburgh.

“I saw a clown fish that looked like Nemo,” says classmate Shannon Duffy.

“I saw a lion fish and it looked like it had a mane and it had black and white stripes.”

Behind the scenes, experts work to keep the animals healthy and comfortable. “We try to create conditions for them to behave naturally according to their instincts,” says Mr Smith. “They are well fed and live about a third longer than they would in the wild.

“A good sign that animals are comfortable in captivity is when they start breeding. Our male sand tiger sharks are just coming to maturity and are beginning to get very interested in the females.

“Smaller members of the shark family, the dogfish, breed quite happily here. So do thornback rays, which lay their eggs in these mermaids’

purses.” He points to a row of hairy brown objects floating in a small tank.

“This little chap hatched out two days ago,” he says, indicating a translucent, diamond-shaped ray one inch across. “Look, you can see his heart beating.”

Moving freely between the behind-the-scenes maintenance and science and the spectacle out front is the aquarium’s team of presenters, who swim with the sharks and talk to the children.

Clad in a red and black wetsuit, Craig Parnham is entertaining a group of youngsters gathered three deep around a rock pool, where he sits gently stroking a devil crab. “Have a feel,” he offers and a few tentatively stretch fingers towards the fiercely clawed but seemingly docile decapod.

“Oh, he’s soft and furry,” says a surprised girl.

“Now why do you think that is?” Craig asks.

To help him swim through the water, suggests one lad. To make girl crabs like him, offers his sister.

“Good ideas,” says Craig, “but in fact it is so he can hide from animals who want to eat him.

“When he’s on the beach he uses his big legs to throw sand on his back and it’s held there by all the little hairs you felt. That helps him blend in with the sand so hungry seagulls can’t see him. It’s an example of camouflage.”

Craig releases the crab from his firm grip and its sturdy legs propel it rapidly downwards and out of sight behind the rocks.

“In this pool we have the most disgusting animal in the world,” Craig continues. After a dramatic build-up he reveals that he means the starfish, which digests live mussels by extruding its stomach and wrapping it around them.

The youngsters could listen to this sort of lesson all day but even dressed in a wet-suit the presenters find temperate rock pools too chilly to linger long. So, after an hour, Craig goes off to mingle with visitors touring the aquarium’s exotic habitats.

There is the tropical coral reef, where angel fish, foxfaces and moon wrasses flutter and dart in the limpid waters.

There are bizarre and deadly sea-creatures hunting their prey.

There is an Amazonian rainforest, where a whole day of frogs’ croaks, insects’ buzz, bird calls, monkey cries and thunderstorms is compressed into 12 minutes.

There is an amphibians’ room where vivid blue frogs pose among glossy green foliage, like models for a Dali watercolour.

The fearsome reputation of the piranha draws young and old alike to a big tank where a dozen float watchfully. Only the unnatural stillness and the wary intelligence in the red eyes give any hint that these fresh-water creatures might erupt in an instant into a frenzy of hungry bloodlust.

“Feeding time for most of the fish and animals is a big attraction,” says education manager Karen Philip, “but with the piranha, if you blink you miss it.”

Strange and fascinating, beautiful and bizarre, all these exotic creatures are, for many visitors, just the warm-up acts to the main event. Deep Sea World styles itself as Scotland’s shark capital and is home to 11 species.

Getting close to some of the most ancient, efficient and, frankly, terrifying carnivores on the planet is the climax of everyone’s visit.

The underwater safari is a winding, perspex-walled tunnel through a huge tank containing a million gallons of sea water and 2,000 assorted fish and other sea creatures, among them five sand tiger sharks, the largest of which is 10ft long and known affectionately as Tinkerbell.

The moving walkway carries visitors through silvery shoals of mackerel, past great flat rays whose exposed underbellies look like grinning faces and into caverns where conger eels lurk in dark crevices.

Suddenly a white shape looms out of shimmering shadows and silence falls on the walkway. The triangular fin, the beady eyes, the wide gash of a mouth with wickedly curving teeth and the undulating air of purpose about the long, sleek shark strike momentary fear into even the bravest.

But a diver cleaning the roof of the tunnel does not spare the sinister shape a glance as it silently passes just inches from his head.

“They are never hungry,” explains Ms Philip, “and they know the divers are the ones who bring them food.

“It’s so safe, in fact, that visitors can book a session of swimming with sharks. We take every kind of precaution. The animals are docile and we have never had an accident. I’ve even done it myself.”

Does knowing it is safe make the experience less exciting?

“I wouldn’t say that. No matter how much you know, the first time you meet a shark underwater your heart misses a beat. It is really scary.”

Deep Sea World is hosting a shark awareness weekend next month to dispel some of the myths surrounding possibly the world’s most misunderstood predator and highlight the plight of sharks and the environmental threats they face.

Zoological manager Matt Kane says: “An estimated 100 million sharks are killed each year, mainly as a result of bycatch and the vast international demand for shark fins for soup.

“As apex predators, sharks maintain the balance of the marine ecosystem and play a vital role in our oceans. Their disappearance could have devastating effects on other fish species.

“Aquariums such as Deep Sea World are pioneering these issues and supporting campaigns to ensure these magnificent creatures are conserved.”

Shark Awareness weekend, August 28-30, including an evening with Mike Rutzen, famous for his free diving with great white sharks, on August 29.

Tickets cost pound;10 and include entry to Deep Sea World, tel 01383 411880

GO ON A VOYAGE OF DISCOVERY

Deep Sea World supports an active educational programme, both on site and through outreach visits to schools. Two types of educational visit are offered: a self-guided tour with a worksheet or scavenger hunt to focus children’s attention, and staff-led classroom sessions on a variety of marine topics.

“We have a programme of talks and workshops aimed at schoolchildren from infants to senior secondary,” says education manager Karen Philip, who was recently appointed from Dundee’s popular science centre Sensation.

“Subjects range from food chains and life in the sea, to sharks, pollution and tropical rainforests. We even have a fun one on pirates.”

The aquatic attraction is developing these and others to make them more hands-on and is keen to offer activities for all age groups. Teachers’

workshop packs for the 5-14 curriculum are available.

Deep Sea World, tel 01383 411880 www.deepseaworld.com